Chain of custody

Last updated

Chain of custody (CoC), in legal contexts, is the chronological documentation or paper trail that records the sequence of custody, control, transfer, analysis, and disposition of materials, including physical or electronic evidence. Of particular importance in criminal cases, the concept is also applied in civil litigation and more broadly in drug testing of athletes and in supply chain management, e.g. to improve the traceability of food products, or to provide assurances that wood products originate from sustainably managed forests. It is often a tedious process that has been required for evidence to be shown legally in court. Now, however, with new portable technology that allows accurate laboratory quality results from the scene of the crime, the chain of custody is often much shorter which means evidence can be processed for court much faster.

Contents

The term is also sometimes used in the fields of history, art history, and archives as a synonym for provenance (meaning the chronology of the ownership, custody or location of a historical object, document or group of documents), which may be an important factor in determining authenticity.

Criminal evidence

When evidence can be used in court to convict persons of crimes, it must be handled in a scrupulously careful manner to prevent tampering or contamination. The idea behind recording the chain of custody is to establish that the alleged evidence is in fact related to the alleged crime, rather than having, for example, been "planted" fraudulently to make someone appear guilty.

Establishing the chain of custody is made of both a chronological and logical procedure, especially important when the evidence consists of fungible goods. In practice, this most often applies to illegal drugs which have been seized by law enforcement personnel. In such cases, the defendant at times disclaims any knowledge of possession of the controlled substance in question. Accordingly, the chain of custody documentation and testimony is presented by the prosecution to establish that the substance in evidence was in fact in the possession of the defendant.

An identifiable person must always have the physical custody of a piece of evidence. In practice, this means that a police officer or detective will take charge of a piece of evidence, document its collection, and hand it over to an evidence clerk for storage in a secure place. These transactions, and every succeeding transaction between the collection of the evidence and its appearance in court, should be completely documented chronologically in order to withstand legal challenges to the authenticity of the evidence. Documentation should include the conditions under which the evidence is gathered, the identity of all evidence handlers, duration of evidence custody, security conditions while handling or storing the evidence, and the manner in which evidence is transferred to subsequent custodians each time a transfer occurs (along with the signatures of persons involved at each step).

Maintaining a chain of custody is essential for the forensic scientist that is working on a specific criminal case. The documentation of evidence is key for maintaining a chain of custody because everything that is done to the piece of evidence must be listed and whoever came in contact with that piece of evidence is accountable for what happens to it. This prevents police officers and other law officials from contaminating the evidence or taking the piece of evidence.

Example

An example of chain of custody would be the recovery of a bloody knife at a murder scene:

  1. Officer Andrew collects the knife and places it into a container, then gives it to forensics technician Bill.
  2. Forensics technician Bill takes the knife to the lab and collects fingerprints and other evidence from the knife. Bill then gives the knife and all evidence gathered from the knife to evidence clerk Charlene.
  3. Charlene then stores the evidence until it is needed, documenting everyone who has accessed the original evidence (the knife, and original copies of the lifted fingerprints).

The chain of custody requires that from the moment the evidence is collected, every transfer of evidence from person to person be documented and that it be provable that nobody else could have accessed that evidence. It is best to keep the number of transfers as low as possible.

In the courtroom, if the defendant questions the chain of custody of the evidence it can be proven that the knife in the evidence room is the same knife found at the crime scene. However, if there are discrepancies and it cannot be proven who had the knife at a particular point in time, then the chain of custody is broken and the defendant can ask to have the resulting evidence declared inadmissible.

Chain of custody is also used in most chemical sampling situations to maintain the integrity of the sample by providing documentation of the control, transfer, and analysis of samples. Chain of custody is especially important in environmental work where sampling can identify the existence of contamination and can be used to identify the responsible party.

Supply chain management

ISO standard 22095, Chain of custody – General terminology and models was published in 2020. The ISO describes this standard as "a simple solution" designed "to help boost manufacturer and consumer confidence, reducing supply chain costs by addressing issues like risk, loss of time and conditions of production". [1]

See also

Related Research Articles

<span class="mw-page-title-main">Forensic science</span> Application of science to criminal and civil laws

Forensic science, also known as criminalistics, is the application of science principles and methods to support legal decision-making in matters of criminal and civil law.

<span class="mw-page-title-main">Authentication</span> Act of proving an assertion, often the identity of a computer system user

Authentication is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. It might involve validating personal identity documents, verifying the authenticity of a website with a digital certificate, determining the age of an artifact by carbon dating, or ensuring that a product or document is not counterfeit.

<span class="mw-page-title-main">Forensic palynology</span> Forensic application of the study of particulate matter

Forensic palynology is a subdiscipline of palynology, that aims to prove or disprove a relationship among objects, people, and places that may pertain to both criminal and civil cases. Pollen can reveal where a person or object has been, because regions of the world, countries, and even different parts of a single garden will have a distinctive pollen assemblage. Pollen evidence can also reveal the season in which a particular object picked up the pollen.

Traceability is the capability to trace something. In some cases, it is interpreted as the ability to verify the history, location, or application of an item by means of documented recorded identification.

DNA paternity testing is the use of DNA profiles to determine whether an individual is the biological parent of another individual. Paternity testing can be especially important when the rights and duties of the father are in issue and a child's paternity is in doubt. Tests can also determine the likelihood of someone being a biological grandparent. Though genetic testing is the most reliable standard, older methods also exist, including ABO blood group typing, analysis of various other proteins and enzymes, or using human leukocyte antigen antigens. The current techniques for paternity testing are using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Paternity testing can now also be performed while the woman is still pregnant from a blood draw.

Circumstantial evidence is evidence that relies on an inference to connect it to a conclusion of fact—such as a fingerprint at the scene of a crime. By contrast, direct evidence supports the truth of an assertion directly—i.e., without need for any additional evidence or inference.

<span class="mw-page-title-main">Crime scene</span> Location that may be associated with a committed crime

A crime scene is any location that may be associated with a committed crime. Crime scenes contain physical evidence that is pertinent to a criminal investigation. This evidence is collected by crime scene investigators (CSI) and law enforcement. The location of a crime scene can be the place where the crime took place or can be any area that contains evidence from the crime itself. Scenes are not only limited to a location, but can be any person, place, or object associated with the criminal behaviours that occurred.

<span class="mw-page-title-main">Trace evidence</span> Type of evidence of physical contact

Trace evidence is created when objects make contact, and material is transferred. This type of evidence is usually not visible to the eye and requires specific tools and techniques to be obtained. Due to this, trace evidence is often overlooked, and investigators must be trained to detect it. This type of evidence can link a victim to suspects and a victim or suspect to the crime scene.

Forensic identification is the application of forensic science, or "forensics", and technology to identify specific objects from the trace evidence they leave, often at a crime scene or the scene of an accident. Forensic means "for the courts".

False evidence, fabricated evidence, forged evidence, fake evidence or tainted evidence is information created or obtained illegally in order to sway the verdict in a court case. Falsified evidence could be created by either side in a case, or by someone sympathetic to either side. Misleading by suppressing evidence can also be considered a form of false evidence ; however, in some cases, suppressed evidence is excluded because it cannot be proved the accused was aware of the items found or of their location. The analysis of evidence may also be forged if the person doing the forensic work finds it easier to fabricate evidence and test results than to perform the actual work involved. Parallel construction is a form of false evidence in which the evidence is truthful but its origins are untruthfully described, at times in order to avoid evidence being excluded as inadmissible due to unlawful means of procurement such as an unlawful search.

<span class="mw-page-title-main">Forensic biology</span> Forensic application of the study of biology

Forensic biology is the use of biological principles and techniques in the context of law enforcement investigations.

<span class="mw-page-title-main">Forensic photography</span> Art of producing an accurate reproduction of a crime scene

Forensic photography may refer to the visual documentation of different aspects that can be found at a crime scene. It may include the documentation of the crime scene, or physical evidence that is either found at a crime scene or already processed in a laboratory. Forensic photography differs from other variations of photography because crime scene photographers usually have a very specific purpose for capturing each image. As a result, the quality of forensic documentation may determine the result of an investigation, in that with the absence of good documentation, investigators may find it impossible to conclude what did or did not happen.

The following outline is provided as an overview of and topical guide to forensic science:

<span class="mw-page-title-main">Forensic footwear evidence</span>

Forensic footwear evidence can be used in legal proceedings to help prove that a shoe was at a crime scene. Footwear evidence is often the most abundant form of evidence at a crime scene and in some cases can prove to be as specific as a fingerprint. Initially investigators will look to identify the make and model of the shoe or trainer which made an impression. This can be done visually or by comparison with evidence in a database; both methods focus heavily on pattern recognition and brand or logo marks. Information about the footwear can be gained from the analysis of wear patterns which are dependent on angle of footfall and weight distribution. Detailed examination of footwear impressions can help to link a specific piece of footwear to a footwear imprint as each shoe will have unique characteristics.

Evidence management is the administration and control of evidence related to an event so that it can be used to prove the circumstances of the event, and so that this proof can be tested by independent parties with confidence that the evidence provided is the evidence collected related to the event.

Forensic entomology deals with the collection of arthropodic evidence and its application, and through a series of tests and previously set rules, the general admissibility of said evidence is determined. Forensic entomology may come into play in a variety of legal cases, including crime scene investigation, abuse and neglect cases, accidents, insect infestation, and food contamination.

Touch DNA, also known as Trace DNA, is a forensic method for analyzing DNA left at the scene of a crime. It is called "touch DNA" because it only requires very small samples, for example from the skin cells left on an object after it has been touched or casually handled, or from footprints. Touch DNA analysis only requires seven or eight cells from the outermost layer of human skin. The technique has been criticized for high rates of false positives due to contamination—for example, fingerprint brushes used by crime scene investigators can transfer trace amounts of skin cells from one surface to another, leading to inaccurate results. Because of the risk of false positives, it is more often used by the defense to help exclude a suspect rather than the prosecution.

<span class="mw-page-title-main">Audio forensics</span>

Audio forensics is the field of forensic science relating to the acquisition, analysis, and evaluation of sound recordings that may ultimately be presented as admissible evidence in a court of law or some other official venue.

<span class="mw-page-title-main">Security bag</span> Heavy duty bag used to contain high-value products or documents or legally sensitive items

A security bag is a heavy duty bag used to contain high-value products or documents or legally sensitive items. Envelopes with security features are called security envelopes as well as security bags. Cash for deposit in a bank is often placed in a special deposit bag with security features. When used to contain items related to a crime, special evidence bags are used. Authentication of signatures and chain of custody are often required.

<span class="mw-page-title-main">Evidence packaging</span> Specialized packaging for physical evidence

Evidence packaging involves the specialized packaging methods and materials used for physical evidence. Items need to be collected at a crime scene or a fire scene, forwarded to a laboratory for forensic analysis, put in secure storage, and used in a courtroom, all while maintaining the chain of custody. Items might include DNA, drugs, hair samples, body parts, blood samples, sperm, knives, vomit, firearms, bullets, fire accelerants, computers, checkbooks, etc.

References

  1. ISO, Suppliers around the world speaking the same language, published 28 October 2020, accessed 3 November 2020